On February 26, the team began working on the third performance test. In this test, the robot was required to pick up the wrench and deposit it in the garage by March 9². The Speed D8ers used the course strategy depicted below, moving directly from the starting position to the wrench, then directly to the garage, and finally to the fuel crank.
In order to control the wrench, the robot needed an additional mechanism. Team members constructed a pronged mechanism made out of a double angle strip and popsicle sticks, which was controlled using a Futaba servo motor. The servo motor was taped to the front of the robot on top of the wooden chassis for the test. Initially, the popsicle sticks were attached to the double angle strip with screws, but the sticks did not stay in place, so electrical tape was found to be a better adhesive. The team also leveled the robot, which was previously angled following the removal of the back wheels, by adding four 6.5” x 1” x 0.25” pieces of wood underneath the chassis. Finally, a QR code stand was added using two 5.5” double angle strips and additional wood. The robot in this stage is shown here.
Team programmers continued to rely solely on time-based movement to complete this test. Trial-and error was used to determine correct distances for the sleep statements within the code, so numerous tests were conducted on March 1 to ensure that the distances to the wrench and the garage were precise. Additional testing was performed to adjust the movement of the servo to the correct height of the wrench when grabbing it, to ensure that an appropriate power level was used to get up the ramp, and to avoid hitting the control panel.
On March 2, the team tested the consistency of the program before conducting an official test. On the first official test, the robot’s wrench mechanism did not successfully enter the holes of the wrench to grab it. The Speed D8ers conducted a successful unofficial test before running a second official test. In the second official test, the robot was too far to the right when attempting to deposit the wrench, so the wrench was only partially deposited. Finally, on the third official test, the robot performed all necessary tasks successfully and even touched the fuel crank to earn bonus consideration from the OSURED team. Following the test, team members discovered that one possible source of error in failed runs was that the capacitors on the IGWAN motors were bent and rubbing against the motors. This possibly caused the left and right motors to run inconsistently. As a result, team members became more vigilant in checking the motors.